Question

A short linear object of length $b$ lies along the axis of a concave mirror of focal length $f$ at a distance u from the pole of the mirror. The size of the image is approximately equal to :

• A. $b{\left(\frac{u-f}{f}\right)}^{\frac{1}{2}}$
• B. $b{\left(\frac{b}{u-f}\right)}^{\frac{1}{2}}$
• C. $b\left(\frac{u-f}{f}\right)$
• D. $b{\left(\frac{f}{u-f}\right)}^2$

Answer 1

The correct option is D $b{\left(\frac{f}{u-f}\right)}^2$

D is the correct option.